GF54.30-P-4001PO Coolant/Washer Fluid Level Voltage Coding, Function
GF54.30-P-4001PO Coolant/washer Fluid Level Voltage Coding, Function
- MODEL 203.0 /2 /7 as of 1.6.05 up to Model Year 8
Diagram for low washer fluid level
a Front SAM control unit with fuse and relay module (N10/1)
ADC Analog/digital converter
S41 Coolant level indicator switch
S42 Windshield washer fluid level indicator switch
The coolant level indicator switch (S41) and windshield washer fluid level indicator switch (S42) are connected in series and are read in by the front SAM control unit with fuse and relay module (N10/1).
Voltage coding
The switch (s1) and the switch (s2) are switched in parallel for voltage coding of resistor (r1) and resistor (r2), the values of resistor (r1) and resistor (r2) must be different. When the switches (s1, s2) are open, these resistors (r1, r2), together with resistor (r3) of the front SAM control unit with fuse and relay module (N10/1), form a voltage divider, which is supplied with the constant voltage (u). The voltage (ue) at the input of the front SAM control unit with fuse and relay module (N10/1) is thus dependent on the positions of switch (s1) and switch (s2) and the values of the resistors (r1, r2, r3). Each switch combination (s1, s2) gives a different voltage value (ue) at the input of the front SAM control unit with fuse and relay module (N10/1).
Evaluation
The voltage (ue) is applied to the input of the analog/digital converter (ADC) of the front SAM control unit with fuse and relay module (N10/1). The analog-to-digital converter (ADC) converts the analog voltage into a digital value. The processor compares the digitalized values with the threshold values stored in a memory and if necessary places the corresponding message "CHECK COOLANT LEVEL" and/ or "CHECK WASHER FLUID LEVEL" on the Controller Area Network bus class B (interior) (CAN-B). The instrument cluster (A1) reads these messages and actuates the multifunction display (A1p13) accordingly.
The warning message "CHECK COOLANT LEVEL" can be acknowledged by pressing the trip odometer reset button (A1s3) on the instrument cluster (A1).
The "Check washer fluid level." warning message is displayed after every trip cycle, it cannot be acknowledged. It is automatically acknowledged after a certain period of time.
Switch status and messages
In total, the coolant level indicator switch (S41) and the windshield washer fluid level indicator switch (S42) provide the following 4 possible switch combinations, resulting in the following warning messages in the multifunction display (A1p13):
- If the coolant level indicator switch (S41) is open and the windshield washer fluid level indicator switch (S42) is open, no warning message appears in the multifunction display (A1p13).
- If the coolant level indicator switch (S41) is open and the windshield washer fluid level indicator switch (S42) is closed, the warning message "CHECK WASHER FLUID LEVEL." appears in the multifunction display (A1p13).
- If the coolant level indicator switch (S41) is closed and the windshield washer fluid level indicator switch (S42) is open, the warning message "CHECK COOLANT LEVEL." appears in the multifunction display (A1p13).
- If the coolant level indicator switch (S41) is closed and the windshield washer fluid level indicator switch (S42) is closed, the warning message "CHECK COOLANT LEVEL." appears in the multifunction display (A1p13). The warning message "CHECK WASHER FLUID LEVEL." has a lower priority and is therefore not displayed directly.
The warning message "CHECK COOLANT LEVEL" can be acknowledged by pressing the trip odometer reset button (A1s3) on the instrument cluster (A1).
The "Check washer fluid level." warning message is displayed after every trip cycle, it cannot be acknowledged. It is automatically acknowledged after a certain period of time.
